Ammonium iron(III) sulfate

  • Ammoniumeisenalaun
  • Iron alum
  • Eisenammoniumalaun
  • FeH4NO8S2
  • NH4Fe ( SO4) 2

Colorless, often by traces of manganese pale purple solid

  • 266.00 g · mol -1 anhydrous
  • 482.19 g · mol -1 dodecahydrate

Fixed

1.71 g · cm -3

39-41 ° C

Very well in water (1240 g · l-1 at 25 ° C)

Dodecahydrate

Attention

Dodecahydrate

Template: Infobox chemical / molecular formula search available

Ammonium iron (III ) sulfate, a salt comprising iron ammonium and sulfate ions. It has the formula NH4Fe (SO4 ) 2

Properties

Ammonium iron (III ) sulfate is water-soluble, pale purple cubic crystals with a density of 1.71 g/cm3 and a molar mass of 266.0 g / mol. With potassium hexacyanoferrate ( II), the yellow prussiate of potash, it forms Prussian blue. It is also a dodecahydrate NH4Fe ( SO4) 2 · 12H2O known with a melting point 39-41 ° C, which is excreted in the anhydrous form when heated from 230 ° C.

Use

Use is ammonium iron ( III) sulfate as an indicator for titrations Volhard. Furthermore, it comes as a mordant in the textile industry and in medicine as an astringent used.

CAS registry number Dangerous Substances Directive (67/548/EEC)
17764
de